In spite of the wide structural diversity exhibited by drug molecules, many drugs and promising drug candidate molecules are highly hydrophobic. Drug hydrophobicity makes formulation of drugs in aqueous-based solvents difficult, particularly for oral gavage or intravenous dosing. Biocompatible aqueous-based solvents for drug dissolution and drug delivery may include, for example, sterile water for injection, normal saline, phosphate buffered saline (PBS), Ringers Lactate, and 5% aqueous dextrose solution. Various organic co-solvents and surfactants may be added to solubilize drug molecules in a predominantly aqueous medium. These co-solvents and surfactants may include DMSO, propylene glycol, ethanol, poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), cremaphor, and TWEEN®. Current needs in drug formulation practice include reducing drug toxicity, increasing in vivo absorption, and improving drug release profiles, particularly through extended release formulations.
Formulation of drug compounds in biocompatible aqueous media is desirable for patient administration. Certain organic co-solvents, such as cremaphor, are known to produce toxic side effects in certain patient groups. When formulating a drug, a practitioner must weigh the benefit offered by the drug in comparison to potential toxic effects produced by the dissolution vehicle.
In view of the foregoing, non-toxic means for dissolving drugs in aqueous media would provide considerable patient benefit. Non-toxic means for dissolving drugs, which also provide extended release of the drug compounds, are also of considerable benefit.